● Covered by 1 source · 2 reportsMedium impact2 negative
September Windows Server Updates Cause Remote Desktop Services Failures
Key points
- September 2026 updates break RDS on Windows Server 2019, 2022, 2025.
- Servers fail after a few hours, preventing new connections.
- Rolling back updates restores functionality but removes security patches.
- A deadlock between RDP and Local Session Manager is a suspected cause.
- September 2026 updates affect Windows Server 2012, Windows 10, and Windows 11.
- The issue prevents RDP connections and makes related tools unresponsive.
- Microsoft provided Group Policy mitigations.
- Microsoft confirmed the issue on Friday.
Remote Desktop Services Failures Reported
Windows administrators are reporting that the September 2026 cumulative updates are causing significant issues with Remote Desktop Services (RDS) on Windows Server 2019, 2022, and 2025 systems. After installing these updates, servers experience failures that prevent users from connecting, often necessitating a hard reset to restore operations.
Symptoms and Impact
The problems typically manifest a few hours after the updates are installed. Existing Remote Desktop sessions may fail to disconnect or log off correctly, and new connection attempts often hang before failing. Some administrators noted that while RDS initially works, it crashes after the first user logs out, preventing further sign-ins. This issue affects all Windows Server releases targeted by the September updates, including KB5122876 for Server 2019, KB5122882 for Server 2022, and KB5122871 for Server 2025.
Suspected Cause and Temporary Fix
One administrator investigating Server 2022 reported a suspected deadlock between Remote Desktop and the Local Session Manager, where the RDP service becomes unresponsive during user logouts. The service hangs at RDPSERVERBASE!WDLIB_Close due to an apparent lack of a timeout. Microsoft has not yet confirmed this as the official cause.
Administrators have found that rolling back the September updates restores Remote Desktop functionality. However, this action also removes the security fixes included in the Patch Tuesday release, leaving systems vulnerable to other exploits.
Updates
- September 2026 updates affect Windows Server 2012, Windows 10, and Windows 11.
- The issue prevents RDP connections and makes related tools unresponsive.
- Microsoft provided Group Policy mitigations.
- Microsoft confirmed the issue on Friday.
✨ This summary was generated by AI from the outlets' reporting listed below. It is not independently verified and may contain errors — check the original sources. How BrevFeed works →
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How outlets covered it
Microsoft confirmed that its September security updates are causing Remote Desktop Services (RDS) failures on Windows Server systems, impacting Windows Server 2012 and later, as well as Windows 10 and 11. This issue prevents RDP connections and can make related tools unresponsive, requiring a hard reset in some cases. Microsoft has provided Group Policy mitigations while it works on a permanent fix.
Microsoft's September 2026 cumulative updates are causing Remote Desktop Services (RDS) failures on Windows Server 2019, 2022, and 2025, preventing user connections and sometimes requiring hard resets. Rolling back the updates resolves the issue but removes security fixes, impacting server stability and security.